Light‐Induced Tyrosine Phosphorylation of BIT in the Rat Suprachiasmatic Nucleus
Light‐Induced Tyrosine Phosphorylation of BIT in the Rat Suprachiasmatic Nucleus
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光诱导大鼠视交叉上核 BIT 酪氨酸磷酸化
DOI：
10.1046/j.1471-4159.2000.0742436.x
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发表时间：
2000
影响因子：
4.7
通讯作者：
K. Nagai
中科院分区：
文献类型：
--
作者：
Yasukazu Nakahata;Nobuaki Okumura;T. Shima;M. Okada;K. Nagai
摘要：使用维持在12 h光照/ 12 h黑暗循环以及恒定黑暗条件下的大鼠研究了下丘脑视交叉上核中蛋白酪氨酸磷酸化的昼夜变化。我们发现BIT（具有基于酪氨酸的激活基序的脑免疫球蛋白样分子）（一种90 - 95 kDa的跨膜糖蛋白）的酪氨酸磷酸化在光照期比黑暗期高，并且在黑暗期光照后增加。在恒定黑暗条件下观察到酪氨酸磷酸化的类似变化，但其幅度弱于12 h光照/12 h黑暗循环。由于BIT的酪氨酸磷酸化形式能够与蛋白酪氨酸磷酸酶SHP-2的Src同源2结构域结合，我们检查了这些蛋白在视交叉上核提取物中的缔合，发现SHP-2与BIT的共沉淀与其酪氨酸磷酸化平行。这些结果表明，BIT的酪氨酸磷酸化可能参与光诱导的昼夜节律钟的夹带。
Abstract: Circadian changes of protein tyrosine phosphorylation in the hypothalamic suprachiasmatic nucleus have been studied using rats maintained under 12‐h light/ 12‐h dark cycles as well as constant dark conditions. We found that tyrosine phosphorylation of BIT (brain immunoglobulin‐like molecule with tyrosine‐based activation motifs), a transmembrane glycoprotein of 90‐95 kDa, was higher in the light period than in the dark period and was increased after light exposure in the dark period. Similar changes in tyrosine phosphorylation were observed under constant dark conditions, but its amplitude was weaker than that in 12‐h light/12‐h dark cycles. As the tyrosine‐phosphorylated form of BIT is able to bind to the Src homology 2 domain of a protein tyrosine phosphatase, SHP‐2, we examined association of these proteins in suprachiasmatic nucleus extracts and found that SHP‐2 was coprecipitated with BIT in parallel with its tyrosine phosphorylation. These results suggest that tyrosine phosphorylation of BIT might be involved in light‐induced entrainment of the circadian clock.
影响因子：
56.9
作者：
GINTY, DD;KORNHAUSER, JM;GREENBERG, ME
通讯作者：
GREENBERG, ME